Dengue fever (UK /ˈdɛŋɡeɪ/ or US /ˈdɛŋɡiː/), also known as breakbone fever, is a mosquito-borne tropical disease caused by the dengue virus. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases the disease develops into the life-threatening dengue hemorrhagic fever, resulting in bleeding, low levels of blood platelets and blood plasma leakage, or into dengue shock syndrome, where dangerously low blood pressure occurs.

The disease is carried by Aedes aegypti mosquitoes, which is oddly enough the same species of mosquito that was just genetically modified and set loose by the millions. The team of researchers that is responsible for this believes that their genetically modified mosquitoes will thin out the indigenous Aedes aegypti population and stifle the current outbreak of Dengue fever.

Aldo Malavasi, president of Moscamed, the Brazilian company that's raising and testing the GM mosquitoes said that, “We need to provide alternatives because the system we have now in Brazil doesn't work.We have thousands and thousands of cases of dengue and that costs a lot for the country. People are unable to work.”

However, many are wondering if this live experiment could go terribly wrong.

Helen Wallace, director of the British environmental group GeneWatch said that “They are even harder to recall than plants are if anything goes wrong.”

Wallace and many others are concerned about the potential unintended consequences of setting these genetically modified mosquitoes loose in the wild. There are many potential hazards to both humans and the local environment. It is unknown what the release of a species like this will do to the food chain. Additionally, the adverse side-effects that could be caused by a bite from a genetically modified insect have not been thoroughly studied.

Some experts have questioned whether this approach will even achieve its stated goal of reducing the Aedes aegypti population. According to Phil Lounibos, an expert on insect ecology and behavior at the University of Florida, the disease will continue to spread through humans even after the Aedes aegypti population is thinned out in one specific area.

“Most dengue is moved around by people not mosquitoes. Even in places with good mosquito control, they can't control dengue because so many infected people are walking around and just a few mosquitoes will maintain endemic dengue,” Lounibos said.

Although the disease is not spread through human to human contact, Lounibos says that just a small amount of mosquitoes could spread the disease, especially in areas where people are more mobile. Lounibos also mentioned the possibility of this experiment disrupting the food chain.